New project 6: The costs and benefits of environmental sensing in budding yeast (Ramanathan) (#33) We have used single-cell experiments, modeling and theory to investigate the costs and benefits of a starvation response (sporulation) in budding yeast. We investigated the variability between individuals in the kinetics of decision-making using sporulation as a model. We found 2.5 fold variability in the timing of sporulation after a population of cells is transferred from rich to starvation medium. By following fluorescent proteins, we divided the period before the second meiotic division into three periods: the time from the start of starvation to induction of the first wave of targets of Ime1, the time from the onset of the first wave to Ml and the time from Ml to Mil. The duration of the three phases is independent of each other demonstrating that they are each subject to intrinsic variability that is the result of differences in the levels of different molecules. This work38 will form the basis for our future experiments, which are designed to investigate the costs and benefits of different strategies for sensing and responding to environmental variables. Sharad Ramanathan became a Bauer Fellow in 2004 and joined CMB in 2006.